In optical transmission systems, a frequency-division multiplexing method is used, inter alia, to allow multiple utilization of a glass fiber, according to which method, light of varying wavelengths, or rather frequencies, is conducted by a glass fiber. Frequency-division multiplexing systems require a device at the transmitter end to produce and modulate the various carriers, and a device at the receiver end to separate and demodulate the various channels. In principle, it is especially cost-effective to realize suitable devices as integrated optical components, when a large-scale production is possible.
In the case of one such known component as described in German Published Patent Application No. 35 06 569 A1, the light received by many channels, which are close together in terms of frequency, is distributed through coupling resonators, and then selectively coupled according to frequency into the so-called useful resonators, so that only the light of one single transmission channel appears in each useful resonator. In the case of this known device, all the resonators are of the Fabry-Perot type. Situated in the spatial proximity of a useful resonator is a photodiode, which is poled in the blocking direction and which serves to detect the channel, given a properly selected energy gap in the material of the useful resonator. Silicon or silicon/germanium alloys are proposed as suitable materials, which, when properly dimensioned, allow both waveguide structures as well as photodiodes to be produced.
Manufacturing this known arrangement entails a complex technology of epitactically growing very thick layers of silicon or silicon/germanium alloys, since the matrix resonator has a spatial, three-dimensional structure.